SBIR-STTR Award

We propose to design, fabricate and test a series of anthropromorphically designed helmets for optical tomographic functional neuroimaging studies. The helmet design will be based on dimensions derived from an existing database generated by laser scanning cranial anthropometry. Arc-like structures that provide mechanical support to springloaded optical fibers will be fabricated, and will be fitted to an adjustable scaffold having a helmet-type design. These arcs, which will embody optimally contoured geometries corresponding to the three dominant head shapes, will be designed to allow placement on the head of a subject in either a frontal or oblique orientation, thus enabling complete access to the any site on the cranium. They will also act as stand-offs that will permit direct visual inspection of fiber-scalp contact. We will also introduce a flexible low-buoyancy mechanical support arm that will serve to offload the weight of the helmet from the subject's head. We also propose to perform repeatability studies on healthy non-balding and nearly bald volunteers of different races, to determine the variability in optical signal levels at various sites on the head associated with a global blood pressure provocation (quantitative Valsalva maneuver). This information will be used to introduce adjustments to the attachment mechanisms of the fiber-optic support arcs to allow for optimal performance of the helmet design. For a select group of volunteers, we will perform finger-tapping studies to assess the ability of the imaging helmet and associated measuring system to provide for repeatable measures of localized hemodynamic changes in response to neural activation. In a subgroup of these, we will also perform functional MR studies using a similar protocol, to independently validate results from the optical studies. Successful completion of the listed aims, combined with additional refinements under a Phase II effort, will provide the research and clinical investigational community with comprehensively designed (hardware and software) and economical optical neuroimaging system capable of evaluating a broad spectrum of functional states.

We plan to expand the development and clinically validate a closed-loop functional neuroimaging system for the purpose of evaluating subjects with traumatic brain injury (TBI). The considered functional Diffuse Optical Tomography (fDOT) imaging system offers a comprehensive solution to the problem of exploring, in real-time, event related hemodynamic responses from essentially area of the head. Supporting this capability has been the development, under Phase I support, of a novel helmet design that can accommodate dense arrays of optical fibers and that can be quickly and easily adapted to comfortably examine essentially any head geometry. Complementing this capability has also been significant advances in instrument system capabilities and analysis software. Still another significant advance, has been the development of a programmable head-shaped calibrating phantom that can accurately mimic essentially any time-varying hemodynamic response with high fidelity and temporal accuracy. This capability is made possible through use of electrochromic materials whose optical properties can be rapidly and accurately modulated by adjustment of the driving voltage. By simply programming the Diffuse Optical Tissue Simulator (DOTS) phantom to mimic clinical findings of interest, true image features can be reliably distinguished from artifact. This unique and patented capability represents a significant advance in the effort to obtain objective and routine system validation of complex physiological states. The experimental plan calls for improvements to our data collection hardware and to update our instrument and analysis software in ways that (i) support examination of larger size data sets and (ii), permit mapping of image features to the underlying anatomy, and to follow this by a clinical study that will explore different aspects of executive function (working memory, language initiation) in healthy volunteers and subjects with TBI. These results will be analyzed to produce statistical maps of group differences for selected parameters from which we can derive composite measures based on multivariate analysis methods. Finally, we will independently validate the image results by comparing the fDOT image findings to fMRI and clinical findings, and to results obtained using our DOTS phantom. The plan development will complement our already advanced imaging system that has attracted growing demand for which systems are in use in eleven leading research centers world-wide. We are confident that the considered system design and capabilities will open a large market opportunity in support of clinical management of TBI and to the neuroscience community. Planned is the development of an inexpensive brain imaging system able to detect and monitor Traumatic Brain Injury, which affects 2.5-6.5 million people and costs an estimated 48.3 billion in the US each year. The core technology will be updated and preliminary results will be followed up with a clinical trial that focuses on analyzing brain function in TBI patients and healthy volunteers. In order to fully validate this technology, results of the clinical trial will be compared to fMRI experiments performed on the same patient population, as well as a dynamic phantom study